Engine starter

Abstract

An engine starter where a pinion, which is engaged or disengaged with a ring gear of the engine to be started, is formed as an integral part of a drive shaft at an end of the drive shaft which is movable in the axial direction thereof while being rotated by an electric motor. The engine starter has no restriction of the root thickness of the pinion or the number of teeth of the pinion, and has a large gear ratio to the ring gear.

What is claimed is: 
     
       1. An engine starter, comprising: an electric motor,   a drive shaft being rotatable by said electric motor, and being movable in the axial direction thereof, and   a pinion adapted to be engaged or disengaged with a ring gear of an engine according to an axial position thereof, said pinion being integrally formed at an end of said drive shaft and having no more than seven teeth.   
     
     
       2. An engine starter of claim 1, further comprising a stopper which is fixed to said drive shaft and an overrun clutch mechanism equipped with a clutch inner, one end thereof being engaged with said drive shaft, said clutch inner having shoulder section disposed in the moving area of said stopper. 
     
     
       3. An engine starter of claim 2, wherein said stopper contacts said shoulder section when said pinion is engaged with said ring gear of the engine. 
     
     
       4. An engine starter of claim 2, wherein said end of the clutch inner is engaged with the drive shaft by spline engagement. 
     
     
       5. An engine starter of claim 1, wherein said electric motor has an armature rotary shaft. 
     
     
       6. An engine starter of claim 5, further comprising a gear mechanism which is connected to said armature rotary shaft and reduces the revolution speed of said armature rotary shaft,   a stopper which is fixed to said drive shaft, and   an overrun clutch mechanism equipped with a clutch inner, one end thereof being engaged with said drive shaft, said clutch inner having a shoulder section disposed in the moving area of said stopper.   
     
     
       7. An engine starter of claim 6, wherein the rotation of said armature rotary shaft is transmitted, via said gear mechanism and said overrun clutch mechanism, to said drive shaft. 
     
     
       8. An engine starter of claim 1, further comprising a plunger which thrusts said drive shaft so as to move said drive shaft in the axial direction thereof.   
     
     
       9. An engine starter of claim 8, further comprising an electromagnetic switch which controls the movement of said plunger and energizes said electric motor.